K +離子微電極

Calibration Meter requirement: Any research grade pH meter with millivolt mode capability. Set meter to millivolt mode.
The MI-442 is standardized using pure potassium chloride (KCl) solutions and again in solutions containing possible interfering ions ( if appropriate). The pure KCl solutions are used to determine probe function. In pure solutions, a 55 mv difference (approximate) will occur
between each tenfold change in concentration. For example, test in 0.001 N KCl, 0.01 N KCl and
0.1 N KCl.
Standardization in solutions containing possible interfering ions is done in order to simulate the actual samples to be analyzed. For example, if your samples contain a known sodium background such as 150 millimoles NaCl then your calibrating standards should also have this background. These are some possible mixtures you could use: 0.001N KCl-0.15 N NaCl,
0.01N KCl-0.15 N NaCl, 0.1N KCl-0.15 N NaCl. The data are then plotted on semilog paper
(See Sample Calibration Curve).

K +離子微電極

Remember! For best results, do the following:
1. Always use standards that bracket the concentration range that you expect to have in
your samples.
2. Always mix your standards to closely match the composition of your samples.
3. Always calibrate using the same volume of standard that you will have as a sample. Example: samples = 50 microliters then standards = 50 microliters

Cleaning
When using the electrodes in solutions containing protein, the MI-442 and the reference electrode should be rinsed with an enzyme cleaning solution such as Terg-a-zyme (Alconox,
Inc.) or a chromic/sulfuric glass cleaning solution after each use for a couple of minutes to
remove the protein from the glass and the reference junction. This will prolong the useful life of the electrodes